Interface reaction of poly-Si/high- k insulator systems studied by hard X-ray photoemission spectroscopy

Abstract

The interface reaction between poly-Si and high- k dielectrics (including HfSiON and HfAlO) have been investigated using hard X-ray ( hν = 5.95 keV) photoemission spectroscopy (HX-PES). HX-PES method has enabled us to probe intrinsic interfacial states without surface conditioning, due to the large escape depth of high energy photoelectrons. From the results of take-off angle dependent data (O 1s and Si 1s core level photoemission spectra), we have found the difference of interfacial reaction concerning poly-Si and high- k dielectrics for their fabrication process. The oxidation proceeded near to surfaces by the difference in the existence of doped boron atom and in the annealing temperature for fabrication process.